mysql错误server PID file could not be found

　　在centos5.2下安装5.1.30的时候出现如下mysql错误

　　MySQL manager orserverPIDfilecould not befound![FAILED]

　　Starting MySQL.Manager of pid-file quit without updating file.[FAILED]mysql

　　查看错误日志

　　默认的mysql错误日志是在/usr/local/mysql/data 下面 more ****.err 有下面的信息

　　090302 02:27:26 mysqld_safe mysqld from pid file /opt/mysql/web2.pid ended

　　090302 02:30:03 mysqld_safe Starting mysqld daemon with databases from /opt/mysql

　　090302 2:30:03 [ERROR] /usr/local/mysql/libexec/mysqld: unknown option'--skip-federated'

　　090302 2:30:03 [ERROR] Aborting

　　解决方法：

　　只要将/etc/my.cnf里面的 skip federated注释掉即可。